Debt and Credit Facility - Summary of Interest Relating to Senior Notes and Revolving Credit Facility (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Debt Instrument [Line Items]
Total interest expense	$ 12.1	$ 12.5	$ 36.5	$ 37.2
Senior Notes and Revolving Credit Facility
Debt Instrument [Line Items]
Interest expense capitalized as construction in progress	(0.9)	(0.2)	(2.3)	(0.6)
Total interest expense	12.1	12.5	36.5	37.2
Revolving Credit Facility
Debt Instrument [Line Items]
Revolving Credit Facility commitment fees and finance cost amortization	0.6	0.3	1.6	1.2
Senior Notes
Debt Instrument [Line Items]
Senior Notes interest expense, including debt issuance cost amortization	$ 12.4	$ 12.4	$ 37.2	$ 36.6